ROK BLOCK 7" (17cm) width blocks out dust, bugs and noise that enters in through the bottom gap of a trailer ramp door when closed. When the trailer ramp door is open ROK BLOCK creates a smoother transition path for moving items over bottom gap. To seal the perimeter of a trailer ramp door or swing doors search ASIN: B0F8R6DY6Y. To seal trailer entrance doors search ASIN: (available soon). For other ROK BLOCK products for Pickup Truck Tailgates (search ASIN: B075PWVW67), for UTV Tailgates (search ASIN: B0D435WZM4). MADE in U.S.A.